AIM:To determine the changes of regional macular retinal thickness(RT)with spectral domain optical coherence tomography(SD-OCT)after successful pars plana vitrectomy(PPV)surgery with inner limiting membrane(ILM)peeling in patients with idiopathic macular hole.

METHODS:A non-randomized retrospective case study on 17 patients(17 eyes)who were hospitalized between March 1, 2011 and June 30, 2013. All 17 eyes had been diagnosed with idiopathic macular hole and thereafter underwent 25G-PPV surgeries performed by the same surgeon with ILM peeling and short-term gas tamponade. In the 6mo-plus follow-up after surgery, these eyes were found to have successful closure in the macular hole. The macular RT of the nine areas in the Early Treatment Diabetic Retinopathy Study was measured by SD-OCT. All patients were applied by SD-OCT with linear scan of the macular. At least four examinations on the operated eye were conducted in contrast to the other normal eye: before the surgery, 3～5wk after the surgery(stage A), 2～3mo after the surgery(stage B), and >6mo after the surgery(stage C).

RESULTS:In stage A, the macular RT of operated eyes in the areas of C, IS, II, IN, OS, OI, ON(263.00±39.48, 313.92±18.35, 311.00±18.02, 335.67±19.91, 280.83±33.74, 269.92±23.32, 307.00±28.40)were significantly thicker than the corresponding areas of the normal fellow eyes(220.51±23.94, 292.08±21.93, 282.50±20.30, 288.33±20.76, 251.25±17.60, 247.75±21.48, 265.17±24.76μm)(P<0.01)with the exception of the IT(291.58±18.97, 280.33±20.82μm)and OT(250.83±21.21, 242.08±24.02μm)(P>0.01). In Stage B, the macular RT in the areas of II, IN, OS(335.67±19.20,319.75±19.20, 273.50±16.89μm)were significantly thicker than the corresponding areas of the normal fellow eyes(286.33±20.46, 293.42±17.64, 252.50±16.32μm)(P<0.01). However, the macular RT of the operated eyes in the areas of C, IS, IT, OI and OT had no statistically significant difference compared with the corresponding areas of the normal fellow eyes(P> 0.01). In Stage C, the macular RT of operated eyes with the areas of IN(321.17±19.71μm)were significantly thicker than the corresponding areas of the normal fellow eyes(296.25±19.57μm)(P<0.01). Meanwhile the other areas of the operated eyes were not significantly different from the normal fellow eyes(P>0.01). Moreover, the macular RT of operated eyes in the areas of ON, IT(307.00±28.40,291.58±18.97μm)in stage A significantly decreased compared to that of the corresponding areas in stage C(276.08±32.39, 278.75±10.19μm)(P<0.01).

CONCLUSION: SD-OCT is a convenient tool for the observation of macular regional changes after macular hole surgery. Macular RT had persistent changes after vitrectomy on eyes with macular hole by SD-OCT. ILM peeling may have caused microstructural changes in wide areas of the macular region after PPV surgery. More support and evidence were provided to the further study of the long-term observation for the structural and function of macular after macular hole surgery.